Navigation system and method therefor

ABSTRACT

A navigation system and a method therefor arranged to be mainly adapted to a driver but the same is as well as adapted to a pedestrian as a portable type according to an embodiment in which devices such as a distance sensor and an azimuth sensor are not used. When information about the passage through which a moving object is moving at this very moment, such as a signal transmitted from a transmitter disposed in each passage, electric waves emitted from an orbit satellite, results of detections made by the distance sensor and the azimuth sensor or information supplied by a user, is supplied, an estimation of a result of a travel through the passage while performing no right or left turn, and an estimation of a result of a travel through a lane the way of which is particularly determined previously are respectively indicated as a travelling line. When a target is set, both the target and the travelling line are indicated on the screen of a display device. Simultaneously, the passage at which the target confronts and a passage which constitutes a proper and correct course from a main passage to the target are indicated. Data about the passage is retrieved by means of codes given such that a group code and a common code are given to each link.

TECHNICAL FIELD

The present invention relates to a navigation system which is mainlyused by a driver of an automobile and a method therefor.

BACKGROUND ART

A conventional navigation system having a storage device, a processingdevice, an input device, a display device, sensors and the like and anavigation method to be executed in the system may be classified intothe following two types on the basis of the contents displayed on thedisplay device as driving information provided for a user.

One of the two types is a map display system which is arranged in such amanner that a map is displayed on the screen of the display device and atravelling locus, a present position, a moving direction, a target, atarget direction, an instructed course or the like are indicated in themap. Another one is an arrow display system which is arranged in such amanner that no map is displayed but arrows respectively showing thetarget direction and the course instruction at each intersection areindicated.

The map display system and the arrow display system respectively haveencountered the following problems:

According to the map display system, a driver must look at the displayedmap while driving a vehicle. Therefore, the driver must pay attention tomany factors and thereby the driver will be exhausted, causing a load tobe applied to the driver. Furthermore, a risk will arise as the case maybe. Therefore, in the conventional map display system, the displaydevice has been disposed in a lower position so that the driver cannotlook at it during driving, or only main roads are indicated duringdriving. However, these devices could not satisfactorily overcome theproblems and thereby a risk in terms of traffic safety remains. Becauseof the risk, the European countries have denied the map display systemand therefore they have not employed the map display system.

The arrow display system encounters the following two typical problems:In a case where the target direction is shown by an arrow as one of thedisplay modes of the display device, the driver psychologically tends toperform earlier turns to the right or left in accordance with the shownarrow, causing a problem to arise, for example, the vehicle strays in aresidential area. Furthermore, in a case where the course is instructedat an intersection as another display mode, timing at which trafficinformation collected in real time is indicated and acceptability forthe drivers, which becomes a serious problem for the aged and femaledrivers, remain as unsolved problems, because there is a courseinstruction as the assumption.

According to a basic system design concept used for developing theconventional navigation system, the most important factor for thenavigation system lies in that the present position of the user'svehicle, which is moving, is accurately recognized in a map (road map)which has been previously prepared. This system design concept issimilarly applied to both the map display system and the arrow displaysystem.

However, the conventional navigation system developed in accordance withthe basic system design concept has been restricted by the system designconcept and thereby it is of no practical use at present.

That is, since the vehicle such as an automobile moves at considerablyhigh speed, it is not so practical for the driver even if the driverrecognizes the present position of the vehicle as a point of lowaccuracy on the road map displayed on the display device. That is, it israther acceptable for the driver who is driving the vehicle, in theaspects of the speed sensibility and the sense about the positionalrelationship and the directional relationship with respect to histarget, that the driver recognizes the state of the vehicle's movementas a line while making the positional relationship with respect to thetarget clear than recognizing the present position indicated as a point,on the screen of the display device. It is easier and more natural forthe driver to recognize the state of the vehicle's movement as the linethan to recognize the state of the movement as the point. Furthermore,information about the state of the movement as the line is more valuableas available drive information. In addition, since the user's vehiclesuch as an automobile must move while being restricted by a road in adifferent manner from an airplane and a ship, it is more practical torecognize the road on which the user's vehicle is moving at a particularmoment while making the positional relationship with the target for theuser's vehicle clear than obtaining the present position of the user'svehicle as a point.

Furthermore, if the present position of the user's vehicle is intendedto be accurately obtained, the load of realizing the high accuracybecomes too heavy for the navigation system. As a result, the cost formanufacturing the navigation system cannot be reduced and thereby wideuse of the navigation system will be interrupted. Therefore, the primaryideal of preventing the traffic snarl and realizing the safety trafficcannot be achieved.

It is very dangerous for the driver to drive his vehicle while actuallylooking for a road. Therefore, there has been a desire of a practicalnavigation system to be developed as a system of aiding the driver toeasily reach the position of the target. According to the conventionalnavigation system arranged in accordance with the map display system,the driver must look for the driving course set on the road mapdisplayed on the display device. Therefore, the dangerous factor cannotbe eliminated and thereby its practicality is insufficient.

Since the driver must pay attention to many things during driving thevehicle, the load of the driver must be reduced for the purpose ofsafely driving the vehicle. Therefore, it is preferable that anavigation system be arranged in such a manner that informationnecessary to select the course can be obtained at first glance.

According to the conventional navigation system arranged in accordancewith a route guide system in which the driving course through which thevehicle reaches the target is indicated on the display device, anoptimum driving course is set in accordance with the relationshipbetween the start position and the target position at the time of startof driving. According to the above-described navigation system arrangedin accordance with the route guide system, it is actually difficult todrive the vehicle while keeping the driving course in the actual roadstate even if the driving course is indicated on the display device.Furthermore, the degree of the danger can be increased due to stressgiven to the driver when the determined driving course is instructed forthe driver.

However, if the instruction by means of indicating the driving course isnot made but only the present position of the user's vehicle isindicated, the value of information is insufficient. It is moredangerous to look for the course in accordance with the present positionshown on the road map displayed on the display device than to instructthe driving course.

It is important for the navigation system to, via the display device,show the driver information which is valuable to reach the target in astate in which safety cannot be deteriorated. In particular, intensestress is given to the driver if the optimum driving course to reach thetarget is determined before the start of driving and the one fixeddriving course is shown to the driver. In order to prevent the state inwhich the stress is given to the driver, it is preferable that thenavigation system be constituted in such a manner that the driver isable to select a course to reach the target and the driver'sdetermination about the selected course is given priority. As a result,the driver is able to drive the vehicle with composure.

Furthermore, the current background in which the aged and the femaledrivers increase must be taken into consideration. In addition, themental state and recognition of the driver in a specific situation mustbe considered.

Therefore, it is insufficient for the display device to indicate thepresent position of the user's vehicle on the road map. In addition, itis an excessive function to indicate the driving course on the map.

An object of the present invention is to provide a significantlypractical navigation system and a method therefor capable of overcomingthe above-described problems and meeting the above-describedrequirements by regarding information about the movement state of amoving object as a line as important and employing a concept of a "linerepresenting a passage through which the moving object is moving at thisvery moment", that is a "travelling line", whereby necessary and minimumpractical information is supplied to a user such as a driver to causethe user to independently select the course.

Another object of the present invention is to provide a navigationsystem and a method therefor in which a novel and practical navigationdisplay system is employed which is completely different from theconventional map display system and the arrow display system in terms ofthe display method and which is arranged completely different from thecourse guide system in terms of a navigation principle such that thedriving course is not set previously but a user is able to independentlymake the driving course while selecting a course in accordance with thedetermination about driving made by the user.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a navigationsystem and a method therefor arranged in such a manner that coordinatesand various data items about positions are stored in a storage device asneeded, a processing device performs a predetermined process whenpredetermined information is supplied via an input device and a displaydevice indicates the result of the process, wherein, when informationabout a passage through which a moving object is moving at this verymoment is supplied by means of any one or some of a receipt of a signaltransmitted from a transmitter, a receipt of satellite electric waves,detections of a distance sensor and an azimuth sensor and an operationof a user, a line (hereinafter referred to as a "travelling line")representing the passage through which the moving object is moving atthis very moment is, together with information about a target such as atarget position, indicated on the screen of the display device whilealways making the positional relationship with the target clear.

The "passage through which the moving object is moving at this verymoment" means a passage through which the "moving object", on which themain unit of the navigation system is mounted, is moving at this verymoment. For example, the passage is a passage the start point of whichis defined by a point at which turning to the right/left is performed atan intersection and the end point of which is defined by a final pointto which the moving object is able to reach in a case where the movingobject moves without performing turning to the right/left after turningto the right/left at the intersection. The passage through which themoving object is moving at this very moment is changed in accordancewith the movement of the moving object while repeating turning to theright/left. Therefore, in principle, information about a particularpassage through which the moving object is moving at this very moment isobtained whenever the passage through which the moving object is movingat this very moment is changed, and when obtaining the information aboutthe passage, a line representing the passage through which the movingobject is moving at this very moment is generated. Thus, the linerepresenting the passage through which the moving object is moving atthis very moment shown on the screen of the display device is updated.The "information about the passage through which the moving object ismoving at this very moment" means information from which data about theshape and the position of the passage through which the moving object ismoving at this very moment can be finally obtained. The meaning of theline representing the passage through which the moving object is movingat this very moment, that is, the "travelling line" will be concretelydescribed later.

The navigation system and the navigation method according to the presentinvention are characterized in that the travelling line (the linerepresenting the passage through which the moving object is moving atthis very moment) and the target for the moving object to reach arealways indicated on the screen of the display device, and a driver orthe like can move to reach the target by selecting freely at thedriver's will a passage through which the driver or the like wants topass on the basis of the recognition of the positional relationshipbetween the travelling line and the target on the screen. The travellingline indicated on the screen of the display device is updated wheneverthe driver selects another passage due to turning to the right/left. Asdescribed above, the travelling line is updated with the movement of themoving object in accordance with a selection of the driving course atthe driver's will or the like. Therefore, the travelling line iscompletely different in terms of its concept from the driving coursewhich is described in the background art and which is previouslydetermined before the start of driving between the start point and thetarget.

The present position of the moving object is indicated on the screen ofthe display device as needed. Since the present position of the movingobject can be ascertained from the conditions when making the travellingline indicated or the positional relationship with the target, theparticular necessity of clearly indicating the present position is notrequired. Furthermore, it is not necessary to, on the screen of thedisplay device, display the road map about a region in which the movingobject is moving at this very moment.

As will be described below, the present invention has a plurality ofembodiments so as to select a proper embodiment in accordance with thepurpose and way of use of the present invention. According to theseembodiments, a variety of configurations for variously generating thetravelling line and states of indication mode on the screen of thedisplay device are explained.

A preferred aspect of the present invention lies in a navigation systemand a method therefor arranged in such a manner that transmitters aredisposed in the passages and a signal to be transmitted from thetransmitter is given data about the shape and the position of thepassage in which the transmitter is disposed, whereby, when a main unitof the navigation system mounted on the moving object and having asignal receiving function receives the signal, a travelling linerepresenting the passage through which the moving object is moving atthis very moment is indicated on the display device. Furthermore, aconfiguration may be constituted in such a manner that a code is givento the signal to be transmitted from the transmitter, data about theshape and the position of the passage is stored in a data storage deviceof the main unit, data about the shape and the position of the passagewhich corresponds to the code read from the signal is retrieved from thedata stored in the storage device on the basis of the code read from thesignal and the travelling line is indicated on the basis of theretrieved data.

A preferred aspect of the present invention lies in a navigation systemand a method therefor arranged in such a manner that data about theshape and the position of a passage is stored in the data storagedevice, data corresponding to the passage through which the movingobject is moving at this very moment is retrieved from data stored inthe data storage device when information which can be recognized by auser when the user moves through the passage and with which the passagethrough which the moving object is moving at this very moment can bespecified and the travelling line is indicated.

A preferred aspect of the invention lies in a navigation system and amethod therefor arranged in such a manner that the present place(present position) is estimated on the basis of satellite electricwaves, or a distance sensor and an azimuth sensor, a passage which isnearest to the estimated present position is discriminated, data aboutthe shape and the position of the passage is retrieved from data storedin a data storage device and it is indicated as a travelling line. Aconfiguration may be employed which is arranged in such a manner that alocus of a passage which can be considered that the moving object haspassed through is obtained on the basis of the estimated presentposition, the passage through which the moving object has passed isdiscriminated on the basis of a result of a comparison made between thelocus and the shape of the passage, data about the shape and theposition of the passage which is positioned in front of the passagethrough which the moving object has passed and through which the movingobject will pass through if it does not turn to the right/left isretrieved from data stored in the data storage device and it isindicated as a travelling line.

A preferred aspect of the present invention lies in a navigation systemand a method therefor arranged in such a manner that it comprises adistance sensor and an azimuth sensor, the passages which intersectseach passage are, together with the state of advancement into theintersection, stored, the distance between the intersections is stored,the distance from the initial movement position is detected by thedistance sensor, the distance from the initial movement position to eachintersection is obtained, the stored distance and said quantity ofdetection are subjected to a collation, the intersection which is passedat the time of the detection is estimated on the basis of the collation,the passage into which the moving object has been advanced is estimatedon the basis of the detected state when the state of the advancementinto the intersection is detected, data about the shape and the positionof the passage into which the moving object has been advanced isretrieved from data stored in the data storage device and a travellingline representing the shape and the position of the passage is indicatedon the display device. Another configuration may be employed in whichthe state of advancement of the user into the intersection is suppliedin place of the detection of the azimuth performed by the azimuth sensorto estimate the passage into which the user has advanced, data about theshape and the position of the passage into which the user has advancedis retrieved from data stored in the data storage device and the passageis indicated as the travelling line.

As described above, according to the present invention, generating andindicating of the travelling line can be realized by a variety ofconfigurations. In the configuration according to the present invention,a passage to the end point of the passage which can be selected if themoving object moves without performing turning to the right/left oralong a course in which the driving is regulated is, as informationnecessary and sufficient for a driver or the like to select a course andin the form of information called the "travelling line", indicated onthe screen of the display device. The concept of the display informationcalled the "travelling line" has not been disclosed according to theconventional navigation systems.

The navigation system and the method therefor according to the presentinvention treat the target for the moving object to reach as follows:

The configuration is constituted in such a manner that the coordinateposition of the target is supplied so that codes about name of thetarget, the number given to the target and the name are supplied toretrieve data about the target on the basis of the supplied informationand information about the target such as the target position isindicated on the screen of the display device.

In a case where information supplied to the main unit or informationsupplied for the purpose of retrieving data about the passage toindicate the travelling line includes information about the presentposition, an area to which both the present position and the targetposition belongs is retrieved and the area is displayed on the displayscreen and as well as the target position and the travelling line onwhich the present position or an equivalent position in place of thepresent position are positioned are indicated on the display screen. Thesupplied information including information about the present position isexemplified by a case in which a signal transmitted from the transmitterincludes information about the position at which the transmitter isdisposed, a case in which inputting is performed in accordance with thename of the intersection, the name of a place, the lot number and thename of the roadside facility, a case in which a specific coordinateposition is supplied, a case in which the code numbers which correspondto elements showing the above-described positions substantially show theequivalent place in place of the present position and a case in whichinformation about the estimated present position is supplied.

As described above, information about the target (for example, thetarget position) and the line (travelling line) representing the passagethrough which the user's vehicle is moving at this very moment arealways indicated on one common display screen. Therefore, the user is,at first sight of the display screen, able to determine the selection ofthe course through which the user is able to reach the target on thebasis of the relationship with the actual driving situation.

That is, when the driver or the like, who is a user, looks at thetravelling line indicated on the display screen, the user is able toquickly, easily, extemporaneously and at free will determine to gostraight along the passage through which the user's vehicles is movingat this very moment, or turn to the right or left into another passagein accordance with the positional relationship with the target.

The travelling line serving as information with which the moving objectis able to reach the target is superior information with which thedetermination is made to conventional information used in theconventional navigation technology such as the locus, the presentposition, the target direction and the moving direction. Furthermore,the configuration according to the present invention is arranged in amanner different from the configuration in which a previously setoptimum driving course, is instructed but the same is arranged in such amanner that the determination made by a driver or the like is givenpriority. Therefore, the load and danger of the driver can be eliminatedfrom the psychological viewpoint and a significantly preferable effectcan be obtained in terms of traffic safety.

In addition, information, that is, the present position of the movingobject is not obtained but only the line representing the passagethrough which the moving object is moving at this very moment must begrasped. Therefore, the restriction involved in the conventional systemin which the driving course and the moving object must be continuouslyaligned with each other on the road map displayed on the display screencan be eliminated. As a result, the load in terms of the accuracyapplied to the navigation system can be reduced.

If information for specifying the passage is once supplied, inaccordance with the most simple configuration, the travelling line canbe generated and indicated. Therefore, the ensuing necessity ofestimating the present position by means of the navigation system can beeliminated to make it serve as the navigation system.

In each mode of the present invention, the configuration is constitutedin such a manner that the present position of the user's vehicle or anequivalent place in place of the present position, an intersection linerepresenting the passage which intersects the passage through which theuser's vehicles is moving at this very moment, the intersection of thetravelling line and the intersection line, the moving direction and thelocus are, as secondary determination information, indicated. As aresult, a variety of requests made in each mode can be met while makingthe indication of the travelling line to be the basic function.

Furthermore, a preferred aspect of the present invention can beconstituted in such a manner that data about the shape and the positionof the passage at which the target confronts is stored in the datastorage device, data about the target position and data about thepassage which confronts the target are retrieved when a target is set,the target position is indicated on the display device and a linerepresenting the passage which confronts the target is indicated on thedisplay device. Another configuration example may be arranged in such amanner that data about the shape and the position of a passage whichconstitutes a course through which the moving object is able to properlycorrectly reach the target from a main passage positioned near thetarget is, together with data about the shape and the position of thepassage at which the target confronts, stored in the data storagedevice. Thus, when a target is set, data about the target position anddata about the shape and the position of the passage at which the targetconfronts are retrieved and data about the shape and the position of thepassage which constitutes the course through which the moving object isable to reach the target is retrieved and the target position and theline representing the passage at which the target confront are indicatedon the display device and as well as the line representing the passagewhich constitutes the course through which the moving object is able toreach the target is indicated on the display device.

As a result of the thus-made configuration, the passage and thetravelling line with which an access to the target can be made areclearly shown on the display screen. Furthermore, by arranging theconfiguration in such a manner that the passage which is able to beadapted to the directional regulation is formed into data and theabove-described passage is indicated or the regulation is clearlyindicated, the moving object is significantly easily able to reach thetarget.

Furthermore, the present invention can be constituted in such a mannerthat the target and the travelling line are not indicated on one displayscreen. According to this example of display, the configuration isconstituted in such a manner that the target direction is retrievedwhile making the central point or arbitrary points of an area displayedon the display screen in which the travelling line is indicated to be astart point and the target direction is, together with the travellingline, indicated by an arrow or the like.

As a result of the thus-arranged configuration, in a case of a mode ofthe present invention in which the present position and an equivalentposition in place of the present position is not used as the assumption,for example, in a case where the travelling line is indicated when auser supplies the name or the code of the passage as information, in acase where it is difficult to display the target and the travelling linein one area due to the restriction caused from data, or in a case wherethe present position cannot be detected due to some trouble, the systemaccording to this mode is able to serve as a supplementary function toaid the driver or the like to select the course. Furthermore, since thetravelling line is indicated, the arrow representing the targetdirection does not trouble the user. Therefore, this mode of the presentinvention is able to serve as a satisfactory effective navigationsystem.

Furthermore, according to the mode of the present invention in which thedistance sensor and the azimuth sensor are not required, the navigationsystem and the method therefor according to the present invention can beutilized as a portable apparatus adaptable to a pedestrian. Alsoaccording to this mode, the travelling line and the target are indicatedin a manner different from the conventional configuration in which themap is displayed. Therefore, the user is able to recognize the directionof movement to reach the target.

Since an effect as a navigation system and a method is obtained becausethe target and the travelling line are indicated on the display screen,the contents of display can be simplified, causing a plurality ofadvantages to be realized.

In a case where the arrow display system, the size of the display screencan be reduced. However, a predetermined size of the display is requiredin the map display system. In a case where the present position isshown, it must be collated with the circumferential state after it hasbeen confirmed in the map. Therefore, background information must besufficiently shown in the map, causing a necessity to arise in that thesize of the display screen must be enlarged.

On the other hand, since background information is an indispensablefactor according to the present invention, the size of the screen can bereduced and as well as a wide area can be displayed as practical andmeaningful information.

By combining the navigation system and the method therefor according tothe present invention with information about traffic snarl, the user isable to previously detour the snarl. Furthermore, an aid system can beprovided with which driving can be performed in such a manner that adriver is able to select a passage to detour the snarl after the driverhas confirmed the actual degree of the traffic snarl.

According to the present invention, by combining with a navigationsystem of another course guide system, it can be provided as informationsource to freely select the course which is deviated from the instructedcourse in a case where although the optimum course has been instructed,the moving object is deviated from the optimum course during driving orin a case where the instructed course is not accepted by a female or theaged driver because the traffic volume is too large in the instructedcourse or the traffic speed is too high in the above-described course.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram which illustrates an embodiment of anavigation system according to the present invention;

FIG. 2 is a flow chart which corresponds to embodiments 1 and 2;

FIG. 3 is a flow chart which corresponds to embodiment 4;

FIG. 4 is a flow chart which corresponds to embodiment 6;

FIG. 5 is a flow chart which corresponds to embodiment 8;

FIG. 6 is a flow chart which corresponds to embodiment 10;

FIG. 7 is a flow chart which corresponds to embodiment 12;

FIG. 8 is a flow chart which corresponds to embodiment 24; and

FIGS. 9, 10 and 11 illustrate typical examples of indication made on thescreen of the display device in a case where the navigation methodaccording to the present invention is carried out.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described hereinafterwith reference to the drawings.

FIG. 1 illustrates the configuration of a navigation system according tothe present invention. The illustrated navigation system collectivelyincludes all of the components. It is preferable that the elements ofthe system may be selectively employed at the time of a practical use asdescribed later. The sequence illustrated by each of the illustratedflow charts partially shows the characteristic sequence of thenavigation method according to the present invention. Therefore, theymay be combined with one another as desired at a practical use.

The navigation system shown in FIG. 1 is composed of two sections. Afirst section comprises a main unit with an auxiliary device, which ismounted on a "moving object" such as an automobile or a human body. Themain unit has a function of receiving a signal given from the outside, afunction of generating data by utilizing its internal device and theauxiliary device and a function of making the obtained signal or data. Asecond section is an external unit disposed on the outside of the mainunit, the second section being a unit for supplying a signal includingrequired information to the main unit. Then, the description will bemade hereinafter on the assumption that the "moving object" is anautomobile. The automobile provided with the main unit is defined as a"user's vehicle".

Referring to FIG. 1, a signal 2 emitted from a transmitter 1 disposed ona passage includes data showing the shape and the position of thepassage on which the transmitter 1 is disposed, or a code for retrievingthe data relating to the passage, or other information about anintersection and a crossing or the like. An orbit satellite 4 irradiateselectric waves 5 including information for estimating the position ofthe user's vehicle. The signal 2 is received by a receiver 3, while theelectric waves 5 are received by a receiver 6.

The transmitter 1 and the orbit satellite 4 correspond to theabove-described external unit.

It is preferable that the transmitting section of the transmitter 1 andthe receiving section of the receiver 3 are respectively housed inchambers each having members for shielding signals on its side and rearportions and arranged in such a manner that an opening is formed in itsfront portion . As a result, a directivity in the transmission and thereceipt of the signal 2 is given.

An azimuth sensor 7 and a distance sensor 8 are devices for use toestimate the present position of the user's vehicle after a travel, theazimuth sensor 7 and the distance sensor 8 being arranged torespectively detect the azimuth and the distance.

A touch panel 9 having a touch panel controller 12, a manipulatingsection 10 and a voice input section 11 respectively receive an inputoperation of an operator such as a driver. A data storage section 14, asdescribed in each embodiment of the present invention to be describedlater, stores any one of required data about the shape and the positionof the passage, information about the intersections and crossings, dataabout the target and the shape and the position of the passage throughwhich the moving object is able to reach to the target, coordinates andother map data in a manner corresponding to each embodiment of thepresent invention. A processing section 23 makes a variety of data itemsto be described later in accordance with a program stored in a storagedevice (not shown in FIG. 1). Means for realizing a variety of functionsas to the variety of data items are defined in the processing section23. The function means will be described with reference to FIG. 1 ineach of the embodiments of the present invention.

In addition, reference numeral 13 designates a display section, 24designates an input section, and 25 designates a reading means.

The processing section 23, the data storage section 14, the displaysection 13, the input section 24, the receivers 3 and 6, the readingmeans 25, the azimuth sensor 7, the distance sensor 8, the touch panelcontroller 12, the touch panel 9, the manipulating section 10 and thevoice input section 11 constitute the above-described main unit and theauxiliary device. The azimuth sensor 7, the distance sensor 8 and thelike are, in actual fact, the auxiliary devices provided for the mainunit.

FIGS. 9, 10 and 11 illustrate examples of indication on the screen ofthe display section 13. Referring to these figures, reference numeral 27designates a target for the use's vehicle to reach, 28 designates theabove-described travelling line, 29, 30 and 31 designate the crossings,32 designates a passage confronting the target, 33 designates a passagewith which the passage confronting the target is able to access a mainpassage, 34 and 35 designate the intersections.

Then, various embodiments realized by the navigation systemthus-constituted will now be described, while assuming a circuit elementblock having a predetermined processing function in the processingsection 23.

Embodiment 1

When information about the passage through which the user's vehicle ismoving at this very moment is supplied to the processing section 23 viathe input section 24, data about the shape and the position of thepassage is read from the data storage section 14 via a retrieval means15. A display processing means 22 generates a travelling line whichrepresents the passage on the basis of data about the shape and theposition of the passage. The travelling line, that is, a linerepresenting the shape and the position of the passage, through whichthe user's vehicles is moving at this very moment, is indicated on thedisplay section 13.

A variety of ways of supplying information about the passage throughwhich the user's vehicle is moving at this very moment to the inputsection 24 and the sources of information of this type to be supplied tothe input section 24 will be described in each of the embodiments to bedescribed later.

When information about the passage through which the user's vehicle ismoving at this very moment is obtained and this passage is indicated, asthe travelling line, on the screen of the display section 13, thescreen, in principle, always indicates information about the target forthe user's vehicle to reach. In a case where the position of the targetcan be indicated on the display screen, it is preferable that theposition of the target should be indicated as information about thetarget. There have been known the configuration and the method of theconventional navigation system for indicating the position of the targeton its display device. An embodiment 24 will be described as an examplerelating to the configuration for always indicating the travelling lineand the position of the target on the display screen. In a case wherethe position of the target cannot clearly be indicated on the displayscreen, another information about target is indicated. This case will bedescribed in an embodiment 28.

According to the above-described configuration, the contents indicatedon the display section 13, that is, at least the displayed travellingline and the target, enable the driver to instantaneously, easily andclearly recognize the positional relationship between the target and thetravelling line. As a result, the driver is able to independently judgeand select the preferable course to approach or reach the target whiletaking the actual state of the travel into consideration.

Furthermore, the present position of the user's vehicle is, as needed,indicated on the display screen.

In general, the passage through which the vehicle travels is formed intodata as a segment between two points given coordinate positions. A database of the navigation system according to the present inventionrelating to the passage is made as follows.

First, the passages are sectioned so as to be formed into data.

The forming of the passages into data is performed in such a manner thatdata is constituted in units of links which can be obtained bysectioning the passages at the intersections. Furthermore, a code isgiven to each link so as to make it to be a subject of a retrieval. Ifthere is a characteristic in the shape of the passage, for example, ifthere is a sharp curve, the shape sometimes is utilized to express thepassage.

Data about the link is, for example, formed into groups to constitutelink groups. The link groups are classified as follows so as to be givencodes so that data is made.

As to the passages (it is preferable that each of the passages be formedinto the same passage for the impression of the driver) which can berespectively considered as one continuous passage in a general rule datais made in such a manner that the start to the end of the passage ismade to be one passage and links which constitute this passage are madeto be one group to which a code is given.

A point of advancement from another passage is made to be a start pointand links which constitute a passage from this start point to the endpoint are formed into one group which constitutes one link group towhich a code is given to make data.

A split point of an exclusive right-turn lane or an exclusive left-turnlane, or that of an exclusive movement lane (or a passage), in whichvehicles must move, is arranged to be a start point. Furthermore, acourse from this start point to the end point of the passage in whichthe vehicle moves in this lane is arranged to be one passage and linkswhich constitute this passage are formed into one group so as to begiven a code as a link group so that data is made.

In each of the cases, it is preferable that a specific code is given toeach link and furthermore a common code is given to each of the linkswhich constitute one group in order to perform a data retrieval on thebasis of these codes.

The arrangements are the basic one for making the data base. However, itis preferable that the data base about the passage be varied asdescribed in each of the following embodiments.

Embodiment 2

The transmitter 1 disposed in a passage transmits the signal 2 includingdata about the shape and the position of the passage. The signal 2 isreceived by the receiver 3 of the main unit. The signal 2 is supplied tothe input section 24 via the reading means 25. At this time, the area ofa plane coordinates in which the passage is positioned is read from thedata storage section 14 by the retrieval means 15 in accordance with thecoordinate position of the passage or the like. The coordinate data anddata about the shape and the position of the passage are indicated onthe display section 13 by the display processing means 22. It ispreferable at this time that sound be generated to inform the user ofthe receipt of the signal 2 when the same is received. It is preferablethat data included in the signal 2 be data about the shape and theposition of the passage from the start point to the end point of thepassage, assuming that the start point is the point at which thetransmitter 1 is disposed, and thereby the coming portion of thetravelling line (the distance from the present position of the user'svehicle in the travelling line) be indicated.

Embodiment 3

In the embodiment 2, data about the position of the transmitter 1 isincluded in the signal 2. As a result, the position of the transmitter 1is indicated on the screen of the display section 13 in addition to thetravelling line.

Embodiment 4

A code is included in the signal 2 transmitted from the transmitter 1disposed in the passage. On the other hand, data about the shape and theposition of the passage which corresponds to the code is stored in thedata storage section 14 of the main unit. When the code is, by means ofthe signal 2, supplied to the processing section 23 via the readingmeans 25 and the input section 24, data about the shape and the positionof the passage is read out from the data storage section 14 by theoperation of the retrieval means 15. In accordance with retrieved data,the travelling line representing the shape and the position of thepassage is then indicated on the display section 13 by the displayprocessing means 22.

Also in this embodiment, it is preferable that the receipt of the signal2 be informed to a user when the same is received by the sound.

Embodiment 5

In the embodiment 4, data about the position of the transmitter 1 isincluded in data to be stored in the data storage section 14 so that theposition of the transmitter 1 is indicated on the display section 13 inaddition to indicating the travelling line.

Embodiment 6

Data about the shape and the position of all of the passages are storedin the data storage section 14. Therefore, when a user (a driver oranother occupant) supplies any one of the name of the passage, that ofthe intersection, the name of a place, the lot number, the name of afacility positioned on the roadside, the coordinate position or a codenumber given to it by the key of the manipulating section 10, the touchpanel 9, the voice input section 11 or the like, data about the shapeand the position of the passage is read from the data storage section 14by the operations of the input sections 24 and the retrieval means 15.As a result, the travelling line is indicated on the display section 13on the basis of the function of the display processing means 22.

Embodiment 7

As the equivalent position to be treated in place of the presentposition of the user's vehicle, position data of a region which isexpressed by the intersection and the name of a place or the lot number,that of the point which is indicated by the facility positioned on theroadside or the coordinates are stored in the data storage section 14 sothat the equivalent position is indicated on the display section 13together with the travelling line.

Embodiment 8

Information about the passage through which the user's vehicle is movingat this very moment is supplied via the input section 24 connected tothe receiver 6 for receiving the electric waves 5, the receiving 3 forreceiving the signal 2, the reading means 25, the distance sensor 7 andthe azimuth sensor 8. Information thus-supplied is made in theprocessing means 16 so that the present place (present position) atwhich the user's vehicle moves is estimated by a present placeestimating means 17. In accordance with the estimated present position,the passage is estimated and discriminated by a passage estimating means18. After the passage has been discriminated, data about the shape andthe position of the passage is read from the data storage section 14 bythe retrieval means 15. Furthermore, it is supplied to the displayprocessing means 22 so that the travelling line representing the shapeof the passage is indicated on the display section 13.

As a method for discriminating the passage through which the user'svehicle is moving at this very moment in accordance with the estimatedpresent position of the user's vehicle, it is preferable that, forexample, an arbitrary points set on the passages are, as data, stored inthe data storage section 14 to perform the nearest point retrieval whilemaking the arbitrary points to be the subject. As a method of settingthe arbitrary point, it is preferable that plural points should be setat long intervals in one passage in a case where there is no adjacentpassage to the one passage, and that the arbitrary point in anotherpassage should be set at a position corresponding to the point set inone passage in a case where there are two passages to be adjacentmutually. As a result of the retrieval performed in such a manner thatthe arbitrary points are respectively treated as the nearest point tothe position of the vehicle, the passage is discriminated by utilizingthe nearest points.

According to the above-described embodiment, data is retrieved inaccordance with the arbitrary point set in the passage, or a linkconstituting the discriminated passage to which the arbitrary pointbelongs. It is preferable that a specific code to a link whichconstitutes the passage is given in addition to the specific link codeto each link to retrieve data about the links. As an alternative tothis, it is preferable that a group code for each link group, which isconstituted by the links, is given to retrieve data formed into a groupby the group code. As an alternative to this, a common code is given tothe specific code to the link which constitutes the passage is given toperform retrieval by the common code.

Embodiment 9

In the above-described embodiment 8, a point on the passage nearest tothe estimated present position may be, together with the travellingline, indicated on the display section 13.

Embodiment 10

When a passed passage is discriminated upon a comparison made betweenthe shape of a locus (passed passages or passages through which thevehicle has already passed) and the shape of the passage based on thestored data, a passage present in front of the passed passage andthrough which the vehicle will run if the user's vehicle does not turnright or left is discriminated by a passage discriminating means 18 onthe basis of the discriminated passed passage. Then, data about theshape and the position of the discriminated passage is read from thedata storage section 14 by the retrieval means 15. As a result, thetravelling line is indicated on the display section 13 by means of thedisplay processing means 22.

According to the above-described embodiment, it is preferable that databe retrieved on the basis of the final link which constitutes the passedpassage.

It is preferable that a specific code is given to a link whichconstitutes the passage from the link to the end point of the same toretrieve data about it, in addition to the specific link code to eachlink. As an alternative to this, it is preferable that a group code foreach link group, which is constituted by the links, is given to retrievedata formed into a group by the group code. As an alternative to this, acommon code is given to the specific code to the link which constitutesthe passage to the end point of the same to perform retrieval by thecommon code.

Embodiment 11

When the travelling line is indicated on the display section 13, theestimated present position is, as the end point of the locus or thestart point of the travelling line, indicated on the display section 13by means of the display processing means 22.

Embodiment 12

The data storage section 14 stores data about the shape and the positionof the passages and, together with the state of advancement at theintersection, stores the distance between intersections and the passageswhich intersect each passage. When information about the start point is,as the initial positional information, supplied through the inputsection 24, each intersection is discriminated by an intersectiondiscriminating means 19 on the basis of both of the distance from thestart point to each intersection calculated in accordance with thestored data, and the actual running distance measured by the distancesensor 8. In accordance with azimuth information detected by the azimuthsensor 7, the passage into which the vehicle has been advanced at theintersection is discriminated by the passage discriminating means 18. Inaccordance with information about the result of the discriminations,data about the shape and the position of the passage into which thevehicle has been advanced is read from the data storage section 14 bythe retrieval means 15.

According to the above-described embodiment, data constituting thediscriminated passage is retrieved. It is preferable that a specificcode to a link which constitutes the passage from the most forward linkto the end point of the passage is given in addition to the specificlink code to the most forward link of the passage into which the vehiclehas been advanced to retrieve data about them. As an alternative tothis, it is preferable that a group code for each link group, which isconstituted by the links, is given to retrieve data formed into a groupby the group code. As an alternative to this, a common code is given toa specific code to a link which constitutes the passage to its end pointis given to perform retrieval by the common code.

Embodiment 13

It is preferable that the position of the estimated passed-intersectionis stored in a storage means 20 to indicate, together with thetravelling line, the estimated passed intersection on the displaysection 13.

Embodiment 14

Although the configuration in the embodiment 12 is arranged in such amanner that the state of the user's vehicle to turn to the right/left isdetected by the azimuth sensor 7, this configuration is arranged in sucha manner that a user inputs the state of turning to the right/left byany one of the voice input section 11, the touch panel 9, and the key orthe switch disposed in the manipulating section 10.

Embodiment 15

The position of the estimated passed-passage is stored in a storagemeans 20 to display, together with the travelling line, thisintersection on the display section 13.

The above-described embodiments 12 and 14 may be modified as follows:

As for the initial movement position, it is preferable that a point ispreviously set, the position of this point is stored in the data storagesection 14 and it is then supplied by means of the code given to thepoint to set the initial movement position.

When the initial movement position is supplied as the coordinateposition of an arbitrary point, the distance from the initial movementposition to an intersection at which the vehicle first turns right orleft is detected by the distance sensor 8. The detected distance isstored in the storage means 20 and the same is collated with thedistance obtained from a means provided in the intersectiondiscriminating means 19 and arranged to calculate the distance from theinitial movement position to each intersection. Thus, the intersectionat which the user's vehicle has turned right or left is discriminated bythe intersection discriminating means 19.

It is preferable that the configuration be arranged in such a mannerthat, when the user's vehicle has once turned to the right or left at anintersection, this intersection is, as the initial movement position,stored in the storage means 20 so as to discriminate the intersection atwhich the vehicle will then turn to the right or left on the basis ofthe stored data.

It is preferable that the distance from a point, which can be set as theinitial movement position, to an intersection on a passage near thepoint is, together with the initial movement position, stored in thedata storage section 14 and make it to be collated with the distancedetected by the distance sensor 8. It is preferable that a code for thepassage to which the point is set is given to data about the point so asto retrieve data about the passage when the point is set as the initialmovement position and it is then indicated as the travelling line on thedisplay section 13.

It is preferable that the point, which is previously set as the initialmovement position, be a facility which can easily be made to be a marksuch as a gasoline station or a roadside restaurant and which relatesthe travel of the vehicle. In this case, it is supplied as a code givento the facility.

As the point which is previously set as the initial movement position,it is also preferable that a plate or the like which is disposed at theintersection or the passage and given a code number or the like be used.

In a case where the initial movement position is an arbitrary position,it can be set on the screen of the display section 13 by using a cursoror it can be set by means of the latitude and the longitude. In order tocalculate the distance, it is preferable that the position be convertedinto coordinate position.

In a case where the azimuth sensor 7 detects the right turn or the leftturn of the user's vehicle, a collation is made between the travelleddistance and the detected data about the right turn or the left turn. Ifthere is not subject intersection, it is preferable that thediscrimination of the intersection be cancelled. The case takes placewhen the lane is changed, the vehicle drops in a parking area or aroadside restaurant, or the right turn or the left turn due to a sharpcurve passage or the like is detected. When the user inputs the state ofthe right or the left turn or when azimuth sensor 7 detects it and aneffective discrimination of the intersection is thereby made, it ispreferable that the cumulative quantity detected by the distance sensor8 is cancelled and counting is again commenced from zero.

In a case where the user inputs the state of the right turn or the leftturn of the user's vehicle, it is preferable that the travelling line isindicated on the display section 13, the nearest intersection positionedforward is shown by an exaggerated enlarged view. Therefore, when thenumber given to the passage in this enlarged view is input by a key orvoice or by directly touching the display screen, the passage to whichthe user's vehicle will be advanced is discriminated.

As another modification, it is preferable that the state of theadvancement be input by voice in such a manner that it is expressed as"right", "upper right", "lower right" and "left". In this case, aconfiguration can be employed in which each advancement state is givenso as to be input by the given number or the same is input in anotherlanguage such as English.

Another modification may be employed which is constituted in such amanner that keys or switches are disposed at the top end section, theintermediate portion and the lower portion of the right side of thescreen frame of the display section 13, the top end portion, theintermediate portion and the lower potion of the left side of the sameand the right portion and the left portion of the lower side of the sameto correspond to the state of the advancement, that is, the upper right,right, lower right, upper left, left, lower left and U-turn.

Embodiment 16

In a case where information about the passage through which the use'svehicle is moving at this very moment includes information about thepresent position of the vehicle, data about the shape and the positionof the subject passage from the present position to the end point of thepassage is retrieved from data stored in the data storage section 14 toindicate the forward portion of the passage through which the vehicle ismoving is at this very moment, as the travelling line, on the displaysection 13 on the basis of the retrieved data.

Embodiment 17

When the travelling line and the locus are indicated on the displaysection 13, the travelling line and the locus are distinguished fromeach other (i.e., highlighted) by being indicated with different kindsof lines or different colors.

Embodiment 18

The display mode on the display section 13 may be arranged in such amanner that the shape and the position of the passage through which theuser's vehicle is moving at this very moment are indicated as thetravelling line, and furthermore, the shape and the position of anotherpassage which intersects the passage through which the user's vehicle ismoving at this very moment are indicated as intersection lines 29, 30and 31.

In this case, it is preferable that the travelling line and theintersection line be distinguished from each other (i.e., highlighted)be being indicated with different colors or different kinds of lines.

Embodiment 19

As a display mode on the display section 13, the position of theintersection may be, together with the travelling line and theintersection line, indicated or the same may be indicated in place ofthe travelling line and the intersection line.

Embodiment 20

As a display mode on the display section 13, the direction of the travelor the direction in which the vehicle must travel may be indicated byusing an arrow or the like in addition to the travelling line.

Embodiment 21

The travelling direction can be indicated on the display section 13 onthe basis of the detection of the travelling direction obtained by theazimuth sensor 7.

Furthermore, when the present position is estimated in accordance withthe satellite electric waves 5, a means for storing the estimated pointand indicating this point on the screen of the display section 13 isprovided, wherein the travelling direction is indicated by continuouspoints, or a direction in the direction of extension of a lineconnecting two or more continuous points including the final point isdefined as the travelling direction, whereby the travelling directiondiscriminating means 21 discriminates the travelling direction inaccordance with the above-made definition so as to indicate thetravelling direction on the display section 13 by an arrow or the like.

Embodiment 22

It is preferable that the locus be indicated together with thetravelling line on the screen of the display section 12.

Embodiment 23

As a display mode to be made on the display section 13, the presentposition or the equivalent position in place of the present position canbe indicated on the display section 13. Furthermore, it is preferablethat the present position or the equivalent position in place of thepresent position be stored in the storage means 20 and a sequentialplurality of stored points are indicated together with the travellingline.

Embodiment 24

The configuration can be formed in such a manner that, in a case whereinput information for retrieving data about the shape and the positionof the passage to be indicated as the travelling line includesinformation about the present position of the user's vehicle, an area towhich both the present position and the target position for the user'svehicle belong is retrieved so as to indicate the area on the displaysection 13, and in addition, the target position, a travelling linehaving the present position or the equivalent position in place of thepresent position thereon may be indicated on the display section 13.

It is preferable that the area to which both the coordinate position ofthe present position or that of the equivalent position in place of thepresent position and that of the target coordinate position belong beretrieved. As an alternative to this, it is preferable that codes for asmall area and a large area set to several stages as being a differentreduced scale to meet a desire are given to a signal transmitted by thetransmitter 1, data to be retrieved in response to this signal, data tobe retrieved by the name of the intersection, the name of a place, a lotnumber, the roadside facility or the like which is supplied by the user,data to be retrieved by the present position or the passed passageestimated in accordance with the result of the satellite electric waveor the detection made by each sensor or data to be retrieved by theintersection at which the user's vehicle has been advanced into adifferent passage. Also data about the target position is given thesimilar area code, whereby a code which is common to them is retrieved.

It is preferable that the area codes for them be retrieved in such amanner that the sequential collation is started form a small area codeto retrieve a code which is common to them. As an alternative to this,the sequential collation is started from a large area code until thearea becomes different in a small area, and then a restoration to thecommon area is made.

As an alternative to this, a configuration can be employed which isarranged in such a manner that a large area to which both the target andthe travelling line belong is displayed, a frame which can be moved andthe size of which can be changed is provided in the display screen andan area to which both the target and the travelling line belong isdetermined and selected by the user's operation of the frame so as todisplay this area. As an alternative to this, either of the target orthe travelling line is first indicated on the display screen and thearea is sequentially changed to a large area by the user until theybelong to the same area.

Embodiment 25

The configuration is constituted in such a manner that the position of atarget for the user's vehicle is stored in the data storage section 14together with data about the shape and the position of the passage atwhich the target confronts. It is preferable that data about theposition of the target be retrieved by the retrieval means 15 when thetarget is set and data of the shape and the position of the passagewhich confronts the target be retrieved to indicate the position of thetarget, the shape and the position of the passage on the display section13.

If a variety of regulations are applied to the passage, for example, ifthere is a directional regulation, it may be shown by an arrow or thelike or the sections through which the vehicle can or cannot pass in thepassage at which the target confronts it may be expressed by differentcolors or different kinds of lines, on the screen of the display section13.

It is preferable that the vehicle type regulation, the hour regulationand weight regulation be indicated on the display section 13 on thebasis of the selection made by the user.

Embodiment 26

The configuration is constituted in such a manner that data about theshape and the position of the passage which constitutes a course throughwhich the vehicle is able to properly and correctly reach from a mainpassage adjacent to the target is stored in the data storage section 14.It is preferable that, when a target is set, the target and the shapeand the position of the passage through which the vehicle reaches thistarget be indicated on the screen of the display section 13.

It is preferable that passages constituting a course to be practicallyadvantageous should be indicated on the display screen in accordancewith the regulation of the law together with the target, and furthermorethe passed intersections and their names, marks for them or the likeshould be indicated similarly.

It is preferable that the main passage which is connected to the passageindicated together with the target and another passage which isconnected to the main passage when the main passage is indicatedtogether with the target are stored in the data storage section 14,whereby, when the above-described another passage is retrieved as thepassage for the user's vehicle, a message "target accessed" is informedto the user by voice or image.

Embodiment 27

It is preferable that, when a target is set, a target direction, thestart point of which is made to be the present position or an equivalentposition in place of the present position, be discriminated by a targetdirection discriminating means 26 and the discriminated target directionbe indicated by an arrow or the like together with the travelling lineon the display section 13.

In a case where the travelling line is indicated while being given apriority on the display screen, for example, in a case where the targetcannot be indicated on the display screen because an enlarged view isdisplayed on the screen of the display section 13 as a result of passingthrough a passage which puzzles the user or a complicated passage, it ispreferable that the target direction should be indicated.

Embodiment 28

The configuration can be constituted in such a manner that, when atarget is set, the target direction, the start point of which is acentral point or an arbitrary point in the area displayed on the displaysection 13 which indicates the travelling line, is discriminated by thetarget direction discriminating means 26. The discriminated targetdirection is, together with the travelling line, indicated by an arrowor the like on the display section 13.

It is preferable that, in a case where the travelling line is indicatedwhile being given a priority on the display screen, for example, in acase where the target cannot be clearly indicated on the display screenbecause an enlarged view is displayed on the display screen as a resultof passing through a passage which puzzles the user or a complicatedpassage, or in a case where information about the present positioncannot be obtained, the target direction should be indicated.

Embodiment 29

It is preferable that, when a novel information item as to the passagethrough which the user's vehicle is moving at this very moment, which isdifferent from information which has been previously supplied, issupplied, data about the novel passage through which the user's vehicleis moving at this very moment is retrieved in accordance with the novelinformation item and a corresponding travelling line is indicated on thedisplay screen, both the travelling line to be indicated in accordancewith the previous input information and the travelling line to beindicated in accordance with the novel input information should beindicated and they should be indicated by different lines or differentcolors so as to distinguish them.

Then, the contents of the processing operation to be performed by theprocessing section 23 will now be described with reference to flowcharts shown in FIGS. 2 to 8. The processing operation to be executed bythe processing section 23 is the navigation method to be executed by thenavigation systems shown in FIG. 1. The operations for respectivelyperforming the navigation methods shown by the above-described flowcharts have basically been described in the above-described respectiveembodiments. Therefore, each navigation operation will now be describedwhile describing the correspondence with the embodiments.

Basically, the navigation method according to the present invention is,as can be seen from the description as to the navigation systems,constituted in such a manner that, when information about the passagethrough which the user's vehicle is moving at this very moment issupplied to the main unit including the processing section 23, the mainunit generates data concerning the travelling line representing theshape and the position of the passage through which the user's vehicleis moving at this very moment in accordance with the information. Then,the travelling line thus-obtained is indicated on the screen of thedisplay section 13 while showing clearly the positional relationshipwith the target.

Specifically, the navigation method according to the present inventionis executed as follows:

First, the signal 2 is, as shown in FIG. 2, received by the receiver 3(step 51). Then, data about the shape and the position of the passagethrough which the user's vehicle is moving at this very moment is read(step 52) so as to retrieve an area which corresponds to the readpassage (step 53). Then, the area and the travelling line are indicatedon the screen of the display section 13 (step 54). For example, thesignal to be supplied to the receiver 3 is, as described in theembodiment 2, the signal transmitted from the transmitter 1. Theabove-described navigation method corresponds to, for example, theembodiments 1 and 2.

As shown in FIG. 3, the signal including the code is received by thereceiver 3 (step 61). Then, the code included in the signal is read(step 62) so as to retrieve data about the passage which corresponds tothe above-described code from the data storage section 14 (step 63).Then, the travelling line is indicated on the screen of the displaysection 13 (step 64). The above-described navigation method correspondsto the embodiment 4.

Another navigation method is, as shown in FIG. 4, constituted in such amanner that information about the passage through which the user'svehicle is moving at this very moment is supplied by the user byoperating the manipulating section 10 or the like (step 71). Then, dataabout the passage which corresponds to supplied information is retrievedfrom the data storage section 14 (step 72) so as to indicate thetravelling line representing the shape and the position of the retrievedpassage on the screen of the display section 13 (step 73). Theabove-described navigation method corresponds to the embodiment 6.

Another navigation method is arranged in such a manner that, wheninformation obtained from the satellite electric waves 5 or the sensors8 and 10 is, as shown in FIG. 5, supplied (step 81), the presentposition of the user's vehicle is estimated in accordance with suppliedinformation (step 82). Then, the passage corresponding to the estimatedpresent position is discriminated (step 83) so that data for indicatingthe travelling line which corresponds to the above-described passage isretrieved from the data storage section 14 (step 84). Then, thetravelling line is indicated on the screen of the display section 13(step 85). The above-described navigation method corresponds to theembodiment 8.

A further navigation method is, as shown in FIG. 6, constituted in sucha manner that, when information of the satellite electric wave 5 or thatobtained as a result of the detection performed by the sensors 8 and 10is supplied (step 91), the present position of the user's vehicle isestimated in accordance with the supplied information and a locus forthe user's vehicle is obtained in accordance with a plurality ofestimated present positions (step 92). Then, the locus thus-obtained anda passage stored in the data storage section 14 are subjected to acomparison (step 93). As a result of this comparison, the passed passageis discriminated (step 94) so as to retrieve data about the forwardpassage from the data storage section 14 in accordance with the passedpassage (step 95). Then, a travelling line representing the shape andthe position of the retrieved passage is indicated on the screen of thedisplay section 13 (step 96). The above-described navigation methodcorresponds to the embodiment 10.

Another navigation method is, as shown in FIG. 7, arranged in such amanner that the initial movement position is set (step 101). Then, thetravelled distance from the initial movement position is detected (step102) so as to store the detected travelled distance (step 103).Furthermore, the distance from the initial movement position to eachintersection is obtained in accordance with data (step 104). Then, theintersection which is passed is estimated from the result of acomparison made between the above-described distance and theabove-described detected travelled distance (step 105). Then, the stateof the advancement into the intersection is detected (step 106) toestimate the advanced passage (step 107) , retrieve data about theadvanced passage (step 108) and indicate the travelling line on thescreen of the display section 13 in accordance with the retrieved data(step 109). The above-described navigation method corresponds to theembodiment 12.

The navigation method shown in FIG. 7 may be arranged in such a mannerthat the travelling line is indicated by a user by inputting the stateof the advancement into the intersection by operating the manipulatingsection 10 in step 106.

Another navigation method is, as shown in FIG. 8, arranged in such amanner that, when the name or the code of a target is supplied (step111), data about the target is retrieved (step 112) and the target isindicated on the screen of the display section 13 in accordance with thedata (step 113). If information about the passage through which theuser's vehicle is moving at this very moment is supplied at this time(step 114), a signal concerning the information is read or dataconcerning the passage is retrieved (step 115). Then, an area to whichboth the present position or an equivalent position in place of thepresent position and the target belong is retrieved (step 116) so thatthe above-described area is displayed on the screen of the displaysection 13. Thus, the target and the travelling line are indicated onthe display screen (step 117). The above-described navigation methodcorresponds to the embodiment 24.

Industrial Applicability

As described above, the navigation system and the method thereforaccording to the present invention are optimum for being mounted on avehicle for use by a driver. Furthermore, it can be used as a portablenavigation system for a pedestrian.

I claim:
 1. A navigation system that displays a road on which an objectis located, without displaying a route to a target comprising a mainunit including a storage device, a central processing device, an inputdevice and a display device, said main unit being mounted on the movingobject and including:road information receiving means for receivinginformation about a shape and a position of a road through which saidmoving object is moving from at least one of an external devicepositioned externally of said main unit and an auxiliary device providedfor said main unit, said shape of said road being determined assumingthat said moving object moves along said road without changing saidroad; a target information indicating means for indicating informationabout the target for said moving object to reach on a screen of saiddisplay device; travelling line generating means for generating a singletravelling line representing only said shape of said road through whichsaid moving object is moving on the basis of said information about theshape and the position of said road that said road information receivingmeans receives, said travelling line generating means changing saidsingle travelling line when said road information receiving meansreceives information indicating that the moving object has changedroads; and a display processing means for displaying said generatedsingle travelling line on the screen of said display device whileindicating the positional relationship of said single travelling linewith said information about said target, said display processing meansdisplaying said single travelling line so that said single travellingline is highlighted with respect to other lines displayed on saidscreen, wherein said single travelling line displayed on said screen ischanged when said moving object changes roads.
 2. A navigation systemaccording to claim 1, whereinsaid external device is a transmittingdevice disposed in each road, said transmitting device having datasupplying means for supplying data about the shape and the position ofsaid road in which said transmitting device is disposed in the form of asignal transmitted from said transmitting device; said storage devicestores data about plane coordinates of areas; said main unit hasreceiving means for receiving said signal transmitted from saidtransmitting device and reading means for reading said data from saidsignal received by said receiving means; said central processing devicehas retrieval means for retrieving one of said areas on said planecoordinates in which said road exists, from said storage device, on thebasis of said data obtained by said reading means; and said roadinformation receiving means retrieves said data about the shape and theposition of said road from an output signal output from said readingmeans, and said travelling line generating means generates said singletravelling line representing only said shape of said road on the basisof both said area obtained by said retrieval means and said data aboutthe shape and the position of said road obtained by said roadinformation receiving means.
 3. A navigation system according to claim1, whereinsaid external device is a transmitting device disposed in eachroad; said transmitting device has code supplying means for supplying aspecific code for said transmitting device to a signal transmitted fromsaid transmitting device; said storage device stores data about theshape and the position of said each road; said main unit has receivingmeans for receiving said signal transmitted from said transmittingdevice and reading means for reading said code from said signal receivedby said receiving means; said central processing device has retrievalmeans for retrieving data about the shape and the position of said roadin which said transmitting device is disposed from said data stored insaid data storage device on the basis of said code obtained by saidreading means; and said travelling line generating means generates saidsingle travelling line representing only said shape of said road on thebasis of said data about the shape and the position of said roadobtained by said retrieval means.
 4. A navigation system according toclaim 1, whereinsaid auxiliary device is an input manipulating devicefor inputting various information items to said input device, saidinformation items being operator recognized items for specifying saidroad during travelling of said road by the operator; said storage devicestores data about the shape and the position of each road; said centralprocessing device has retrieval means for retrieving data about theshape and the position of a corresponding road from said storage devicewhen said operator inputs said various information items into said inputdevice by operating said input manipulating device; and said travellingline generating means generates said single travelling line representingonly said shape of said road on the basis of said data obtained by saidretrieval means.
 5. A navigation system according to claim 4,whereinsaid various information items are any one of the name of a road,the name of an intersection, the name of a place, a lot number, the nameof a facility on the roadside and the coordinate position, or a codenumber given to each of these information items.
 6. A navigation systemaccording to claim 1, whereinsaid external device is a satellite foremitting electric waves including positional information; said storagedevice stores data about the shape and the position of each passage;said central processing device includes present position estimatingmeans for estimating the present position of said moving object on thebasis of said electric wave emitted from said satellite, passagediscriminating means for discriminating a passage nearest to saidpresent position when said present position is obtained by said presentposition estimating means, and retrieving means for retrieving dataabout the shape and the position of said road from data stored in saidstorage device; and said travelling line generating means generates saidsingle travelling line representing only said shape of said road on thebasis of said data about the shape and the position of said roadobtained by said retrieval means.
 7. A navigation system according toclaim 6, whereinsaid central processing device has retrieval means forretrieving data about a point near said estimated present position andsaid display processing means indicates said retrieved point on saidsingle travelling line displayed on said display device.
 8. A navigationsystem according to claim 1, whereinsaid external device is a satellitefor emitting electric waves including positional information; saidstorage device stores data about the shape and the position of eachroad; said central processing device includes a present positionestimating means for estimating the present position of said movingobject on the basis of said electric waves emitted from said satellite,a road discriminating means for discriminating a passed road bycomparing a locus obtained on the basis of said estimated presentposition and said shape of said road stored in said storage device, andretrieving means for, using data stored in said storage device,retrieving data about the shape and the position of a road which is infront of said passed road and will be a passage when no turning toright/left is made, when said passed road is discriminated as a resultof the comparison; and said travelling line generating means generatessaid single travelling line representing only said shape of said roadthrough which said moving object is moving on the basis of saidretrieved data.
 9. A navigation system according to claim 8, whereinsaidsingle travelling line is indicated in such a manner that said estimatedpresent position is made to be the start point of said single travellingline.
 10. A navigation system according to claim 1, whereinsaidauxiliary device includes a distance sensor for detecting a travelleddistance and an azimuth sensor for detecting a direction of a travel;said storage device stores data about the shape and the position of eachroad, roads intersecting each road, a state of advancement at eachintersection and the distance between intersections in each road; saidcentral processing device has means for setting an initial movementposition, means for storing the detected quantity of the distance fromsaid initial movement position detected by said distance sensor, meansfor obtaining the distance from said initial movement position to eachintersection, means for collating said distance and said detectedquantity, means for estimating intersections passed at the time of saiddetection when said collation has been made, means for, when saidazimuth sensor detects the state of advancement into an intersection,estimating a road into which an advancement is made on the basis of saiddetected state and means for retrieving data about the shape and theposition of said road into which said advancement is made from datastored in said storage device; and said travelling line generating meansgenerates said single travelling line representing only said shape ofsaid road on the basis of said retrieved data.
 11. A navigation systemaccording to claim 1, whereinsaid auxiliary device includes a distancesensor for detecting a travelled distance and input manipulating meansfor inputting, by an operator, a state of advancement at an intersectionfrom a road through which a moving object is moving to another road;said storage device stores data about the shape and the position of eachroad, roads intersecting each road, a state of advancement at anintersection and distance between intersections in each road; saidcentral processing device has means for setting an initial movementposition, means for storing the detected quantity of the distance fromsaid initial movement position detected by said distance sensor, meansfor obtaining the distance from said initial movement position to eachintersection, means for collating said distance and said detectedquantity, means for estimating intersections passed at the time of saiddetection when said collation has been made, means for estimating a roadinto which an advancement is made on the basis of said state ofadvancement into another road at said intersection supplied by saidoperator, and means for retrieving data about the shape and the positionof said road into which said advancement is made from data stored insaid storage device; and said travelling line generating means generatessaid single travelling line representing only said shape of said road onthe basis of said retrieved data.
 12. A navigation system according toclaim 1, whereinsaid central processing device has retrieval means forretrieving data about the shape and the position of said road from thepresent position of said moving object to the end point of said roadthrough which said moving object is moving in a case where informationabout the present position is objected on the basis of said informationabout the shape and the position of said road through which said movingobject is moving; and said display processing means includes forwardportion displaying means for displaying a forward portion of said roadthrough which said moving object is moving as said single travellingline representing only said shape of said road on the screen of saiddisplay device on the basis of said retrieved data.
 13. A navigationsystem according to claim 2, whereinsaid data supplied from saidtransmitting device includes data about the shape and the position ofanother road which intersects said road through which said moving objectis moving, and a line representing said another road through which saidmoving object is moving, displayed on the screen of said display deviceas an intersection line.
 14. A navigation system according to claim 3,whereinsaid storage device stores data about the shape and the positionof each road and data about the shape and the position of a road whichintersects each of said roads, said retrieval means as well as retrievesdata about the shape and the position of said road which intersects saidroad when said retrieval means retrieves data about the shape and theposition of said road in which said transmitting device is disposed fromdata stored in said storage device, and along with said singletravelling line representing only said shape of said road through whichsaid moving object is moving, a line representing said other road isdisplayed on the screen of said display device as an intersection line.15. A navigation system according to claim 1, whereinin a case whereinformation about the present position of said moving object is includedin said information obtained by said road information receiving meansabout the shape and the position of said road through which said movingobject is moving, an area to which both said present position and theposition of said target belong is retrieved, and said target and saidsingle travelling line on which said present position or an equivalentposition in place of said present position is present are displayed onthe screen of said display device.
 16. A navigation system according toclaim 15, whereinsaid storage device stores said position of said targetby means of the coordinate position and data about the shape and theposition of a road which confronts said target, said data about saidposition of said target is retrieved when a target is set, also dataabout the shape and the position of said road which confronts saidtarget is retrieved, and said target and a line representing said roadwhich confronts said target are indicated on the screen of said displaydevice.
 17. A navigation system according to claim 16, whereinsaidstorage device further stores data about the shape and the position of aroad which constitutes a course which properly correctly reaches saidtarget from a main road near said target, data about said target anddata about the shape and the position of said road which confronts saidtarget are retrieved when a target is set, also data about the shape andthe position of said road which constitutes said course is retrieved andsaid position of said target, a line representing said road whichconfronts said target and a line representing said road whichconstitutes said course are displayed on the screen of said displaydevice.
 18. A navigation system according to claim 1, whereinsaidcentral processing device has means for retrieving a direction of saidtarget while making an arbitrary point of an area displayed on thescreen of said display device to be a start point when said target isset and said display processing means displays said single travellingline representing only said shape of said road and an arrow representingsaid direction of said target on the screen of said display device. 19.A navigation system according to claim 1, whereinwhen, as to said roadthrough which said moving object is moving, novel information differentfrom said information which has been supplied is supplied, said data isretrieved on the basis of said novel information and a linecorresponding to said novel information is displayed on said displaydevice on the basis of said retrieved data, single travelling linegenerated by said previous information and said line generated by saidnovel information and displayed together on the screen of said displaydevice in such a manner that said two lines are indicated by differentkinds of lines or different colors.
 20. A navigation system according toclaim 1, whereinsaid auxiliary device is a distance sensor for detectinga travelled distance and an azimuth sensor for detecting a travellingdirection; said storage device stores data about the shape and theposition of each road; said central processing device includes presentposition estimating means for estimating the present position of saidmoving object on the basis of positional information detected by saiddistance sensor and said azimuth sensor, road discriminating means fordiscriminating, when said present position is obtained by said presentposition estimating means, a road which is nearest to said presentposition and retrieval means for retrieving data about the shape and theposition of said road from data stored in said storage device; and saidtravelling line generating means generates said single travelling linerepresenting only said shape of said road on the basis of said dataabout the shape and the position of said road obtained by said retrievalmeans.
 21. A navigation system according to claim 1, whereinsaidauxiliary device is a distance sensor for detecting the travelleddistance and an azimuth sensor for detecting a travelling direction;said storage device stores data about the shape and the position of eachroad; said central processing device includes present positionestimating means for estimating the present position detected by saiddistance sensor and said azimuth sensor, road discriminating means forobtaining a locus on the basis of said estimated present position,comparing said locus and the shape of said road stored in said storagedevice and discriminating a passed road and retrieval means for, whensaid passed road has been discriminated after said comparison betweensaid locus and said shape of said road has been performed, retrievingdata about the shape and the position of a road in front of said roadand through which said moving object travels if the same does not turnright or left from data stored in said storage device; and saidtravelling line generating means generates said single travelling linerepresenting only said shape of said road through which said movingobject is moving on the basis of said retrieved data.
 22. A navigationmethod of generating information about a moving state of a moving objectand displaying said information on a display device, said navigationmethod displaying a road on which the moving object is located withoutdisplaying a route to a target and comprising the steps of:settinginformation about the target for said moving object to reach; obtaininginformation about a shape and a position of a road through which saidmoving object is moving, said shape of said road being determinedassuming that said moving object moves along said road without changingsaid road; generating a single travelling line representing only saidshape of said road through which said moving object is moving on thebasis of said information about the shape and the position of said road,said generated single travelling line changing when said informationabout the shape and the position of the road indicates that the movingobject has changed roads; and displaying both of said information aboutsaid target and said single travelling line on a screen of said displaydevice, wherein said single travelling line on said screen is changedwhenever said moving object changes roads, said single travelling linebeing displayed so that said single travelling line is highlighted in amanner that is distinct from other line on said screen.
 23. A navigationsystem according to claim 22, whereinsaid information about the shapeand the position of said road through which said moving object is movingis obtained by receiving a signal including data about the shape and theposition of said road through which said moving object is moving that istransmitted from a transmitting device disposed in each road.
 24. Anavigation system according to claim 22, whereina signal including acode for specifying said road through which said moving object is movingis transmitted from a transmitting device disposed in each road, andsaid information about the shape and the position of said road isobtained by receiving said signal and based on data stored in a storagedevice.
 25. A navigation system according to claim 22, whereinanoperator inputs various information items which are recognized at thetime of a movement through said road as items for specifying said road,and said information about the shape and the position of said road isgenerated on the basis of said various information items.
 26. Anavigation system according to claim 25, whereinsaid various items areany one of the name of a road, the name of an intersection, the name ofa place, a lot number, the name of a facility on a roadside, acoordinate position or a code number given to these information items.27. A navigation method according to claim 22, whereinelectric wavesincluding positional information and emitted from a satellite arereceived, the present position of said moving object is estimated on thebasis of said positional information supplied from said satellite, aroad which is nearest to said present position is discriminated whensaid present position is obtained and said information about the shapeand the position of said road is generated on the basis of said nearestroad.
 28. A navigation method according to claim 27, whereindata about apoint near said estimated present position is retrieved and saidretrieved point is indicated on said single travelling line displayed onsaid display device.
 29. A navigation method according to claim 22,whereinthe present position of said moving object is estimated, thetravelling locus of said moving object is obtained on the basis of saidestimated present position, said locus thus-obtained is subjected to acomparison with previously-prepared data about the shape and theposition of a road, a road in which the latest present position isincluded is obtained by making a retrieval and a line representing saidretrieved road is displayed on said screen of said display device.
 30. Anavigation method according to claim 29, whereinthe indication isperformed in such a manner that said estimated present position is madeto be the initial end portion of said single travelling line.
 31. Anavigation method according to claim 22, whereindata about the shape andthe position of each road, roads intersecting each road, the state ofadvancement at each intersection and the distance between intersectionsin each road are previously prepared in a storage device, the distancefrom an initial movement position is detected by a distance sensor tostore it in a case where said initial movement position is set, thedistance from said initial movement position to each intersection isobtained, said distance and said detected quantity are compared witheach other, an intersection which is passed at the time of detection isestimated, a road into which said moving object has been advanced isestimated on the basis of the detected state of said advancement intosaid intersection when the same is detected, data about the shape andthe position of said road in which said moving object has been advancedis retrieved from data stored in said storage device, a linerepresenting said road is generated on the basis of said retrieved dataand said line is indicated on said display device.
 32. A navigationmethod according to claim 22, whereina distance sensor for detecting thetravelled distance and input manipulating means for, by an operator,inputting the state of an advancement from a road through which saidmoving object is moving into another road at an intersection areutilized; data about the shape and the position of each road, roadsintersecting each road, the state of advancement at each intersectionand the distance between intersection in each road are previouslyprepared in a storage device; when an initial movement is set, thedistance from said initial movement position is detected by saiddistance sensor to store it, the distance from said initial movementposition to each intersection is obtained, said distance and saiddetected quantity are compared, an intersection which is passed at thetime of detection is estimated, said road into which said moving objecthas been advanced is estimated from the state of advancement intoanother road at said intersection supplied by said operator, data aboutthe shape and the position of said road into which said moving objecthas been advanced is retrieved from data stored in said storage device,a line representing said road is generated on the basis of saidretrieved data and said line is indicated on said display device.
 33. Anavigation method according to claim 22, whereinin a case whereinformation about the present position of said moving object is obtainedon the basis of said information about the shape and the position ofsaid road through which said moving object is moving, data about theshape and the position of said road from said present position to theend position of said road through which said moving object is moving isretrieved from data stored in said storage device and the forwardportion of said road through which said moving object is moving is, assaid single travelling line representing only said shape of said road,displayed on said display device on the basis of said retrieved data.34. A navigation method according to claim 22, whereinanother roadintersecting said road through which said moving object is moving is, asa line intersecting said single travelling line, displayed on saiddisplay device.
 35. A navigation method according to claim 22, whereinina case where information about the present position of said movingobject is included in information about the shape and the position ofsaid road though which said moving object is moving, said presentposition or an equivalent position in place of said present position isindicated on said single travelling line.
 36. A navigation methodaccording to claim 22, whereina line representing a road confrontingsaid target is displayed on the screen of said display device.
 37. Anavigation method according to claim 36, whereinsaid line representingsaid road confronting said target, a line representing a main road nearsaid target and a line representing a road which constitutes a coursethrough which said moving object is able to properly correctly reachsaid target from said main road are displayed on the screen of saiddisplay device.
 38. A navigation method according to claim 22,whereinwhen a target is set, a direction of said target is retrievedwhile making an arbitrary point in an area displayed on the screen ofsaid display device to be a start point and single travelling linerepresenting said road and an arrow representing said direction of saidtarget are displayed on the screen of said display device.
 39. Anavigation method according to claim 22, whereinwhen novel informationabout said road through which said moving object is moving differentfrom previous information which has been supplied is supplied, said datais retrieved on the basis of said novel information and a linecorresponding to said novel information is indicated on said displaydevice on the basis of said retrieval data, said single travelling linegenerated by said previous information and said line generated by saidnovel information are displayed together on the screen of said displaydevice in such a manner that said two lines are indicated by differentkinds of lines or different colors.